Results 31 to 40 of about 676,988 (164)

Degree of ill-posedness of statistical inverse problems [PDF]

, 2004
We introduce the notion of the degree of ill--posedness of linear operators in operator equations between Hilbert spaces. For specific assumptions on the noise this quantity can be computed explicitely.
Mathé, Peter
core   +1 more source

Almost optimal local well-posedness for modified Boussinesq equations

Electronic Journal of Differential Equations, 2020
In this article, we investigate a class of modified Boussinesq equations, for which we provide first an alternate proof of local well-posedness in the space $(H^s\cap L^\infty)\times (H^s\cap L^\infty)(\mathbb{R})$ ($s\geq 0$) to the one obtained by
Dan-Andrei Geba, Bai Lin
doaj  

Recovery from electrode position uncertainties in geophysical electrical resistance tomography – Application to moisture transport imaging

Near Surface Geophysics, EarlyView.
Abstract In studies of subsurface hydrology, monitoring and imaging techniques are used to estimate the moisture content, or to track moisture or injected tracer movement. One applied imaging technique is electrical resistance tomography (ERT), in which measurements collected using electrodes placed on the ground surface or in boreholes are used to ...
Mikko Räsänen, Ruanui Nicholson, Jari Kaipio, Aku Ursin   +3 more
wiley   +1 more source

Propagation of internal gravity waves: Optimal vertical discretisation and grid design based on numerical error analysis

Quarterly Journal of the Royal Meteorological Society, EarlyView.
An energy‐conserving discrete framework for the vertical discretisation of stratified ocean models is developed using internal gravity‐wave theory. A β$$ \beta $$‐indexed family of schemes is analysed through perturbation theory, revealing optimal parameter choices and grid designs that reduce truncation errors significantly.
Gabriel Derrida, Laurent Debreu, Florian Lemarié, Jérome Chanut   +3 more
wiley   +1 more source

The ill-posedness of the (non-)periodic traveling wave solution for the deformed continuous Heisenberg spin equation

Open Mathematics
Based on an equivalent derivative non-linear Schrödinger equation, we derive some periodic and non-periodic two-parameter solutions of the deformed continuous Heisenberg spin (DCHS) equation.
Zhong Penghong, Chen Xingfa, Chen Ye
doaj   +1 more source

Classification of structural MRI images in Alzheimer's disease from the perspective of ill-posed problems. [PDF]

PLoS ONE, 2012
BACKGROUND:Machine learning neuroimaging researchers have often relied on regularization techniques when classifying MRI images. Although these were originally introduced to deal with "ill-posed" problems it is rare to find studies that evaluate the ill ...
Ramon Casanova, Fang-Chi Hsu, Mark A Espeland, Alzheimer's Disease Neuroimaging Initiative   +3 more
doaj   +1 more source

3D Character Reconstruction from Hand‐drawn Model Sheets

Computer Graphics Forum, EarlyView.
Abstract Hand‐drawn model sheets are widely used in character design to define 3D shape and appearance through sparse multi‐view drawings. Reconstructing 3D characters from such sparse inputs has traditionally been challenging due to insufficient visual information.
Hyejeong Yoon, Wonjong Jang, Yoonha Hwang, Seungyong Lee   +3 more
wiley   +1 more source

Controlling semi-convergence phenomenon in non-stationary simultaneous iterative methods [PDF]

Iranian Journal of Numerical Analysis and Optimization, 2016
When applying the non-stationary simultaneous iterative methods for solving an ill-posed set of linear equations, the error usually initially decreases but after some iterations, depending on the amount of noise in the data, and the degree of ill ...
Touraj Nikazad, Mehdi Karimpour
doaj   +1 more source

Specification Tests for Jump‐Diffusion Models Based on the Characteristic Function

International Statistical Review, EarlyView.
Summary Goodness‐of‐fit tests are suggested for several popular jump‐diffusion processes. The suggested test statistics utilise the marginal characteristic function of the model and its L2‐type discrepancy from an empirical counterpart. Model parameters are estimated either by minimising the aforementioned L2‐type discrepancy or by maximum likelihood ...
Gerrit Lodewicus Grobler, Denis Belomestny, Simos George Meintanis, Emanuele Taufer   +3 more
wiley   +1 more source

One characteristic problem for the general hyperbolic differential equation of the third order with nonmultiple characteristics

Vestnik Samarskogo Gosudarstvennogo Tehničeskogo Universiteta. Seriâ: Fiziko-Matematičeskie Nauki, 2012
In the paper we consider the well-posed characteristic problem for the general hyperbolic differential equation of the third order with nonmultiple characteristics. The solution of this problem is constructed in an explicit form. The illustrative example
Julia O Yakovleva
doaj   +3 more sources